sim shared by 2 groups

[tabletopfreak Toocool]

hi, im looking to get a sim and have a sky platform with its own 10k prims, yes i know i cant parcel it or dead to 2 groups, but can i make it so the top lvl people have their own tag so i can easily keep their prim in check.. maybe a 3rd party solution .. they would have people coming and going so i know i could keep track on a player to play bases but im looking for a better way, and what height does voice fall off ?? thanks